Yes. The whole line from Framingham to Mansfield is being upgraded right this second to Class 2 standards. Go spotting the line and you'll see Iowa Pacific-contracted crews out there right now doing track work on the southern end of the line (after doing the north end last year). These upgrades will allow for 30 MPH passenger MAS and 25 MPH freight MAS, and also a much smoother and quieter ride now that the shot trackbed and crossing surfaces are getting a long overdue full renewal. Crossing protection is also being upgraded to full gates, meaning Boston trains won't have to slow up at formerly flashers-only crossings like Summer St. in South Walpole and the Providence game-day trains won't get slowed up on the 7 flashers-only public crossings in Foxboro coming up from the Mansfield end.

F-line to Dudley via Park wrote:Yes. The whole line from Framingham to Mansfield is being upgraded right this second to Class 2 standards. Go spotting the line and you'll see Iowa Pacific-contracted crews out there right now doing track work on the southern end of the line (after doing the north end last year). These upgrades will allow for 30 MPH passenger MAS and 25 MPH freight MAS, and also a much smoother and quieter ride now that the shot trackbed and crossing surfaces are getting a long overdue full renewal. Crossing protection is also being upgraded to full gates, meaning Boston trains won't have to slow up at formerly flashers-only crossings like Summer St. in South Walpole and the Providence game-day trains won't get slowed up on the 7 flashers-only public crossings in Foxboro coming up from the Mansfield end.

About how many minutes will the above upgrades shave off on the Boston to Foxboro game trains?

Probably not a whole lot when ~20 miles of the game train trip is on the main + NEC, and only 3.5 miles are on the Framingham Secondary itself. The modest increase in max speed won't shave enough time to get out of the schedule padding margin-of-error. The running track uprate is more about smoother ride quality and lowered noise impacts; you won't ker-plunk up and down with a bang on every shot rail joint like before on the new rail and renewed trackbed. Where you may indeed see the game trains pick up a couple minutes is with the grade crossing rebuilds and Lewis Wye renewal. The wye won't be as excruciating a slow walk with the interlocking due to be rebuilt before the pilot, and both Summer St. Walpole and the Walpole Station pedestrian crossing on the wye are getting full gates as part of their renewal. That does meaningful good at taming speed restrictions across those 3.5 miles.

The full-build feasibility study called for Class 3 (60 MPH MAS) track on the Framingham Secondary from Lewis Wye to Gillette Stadium (no Class 4/79 MPH MAS necessary since trains on the Framingham Sec. would only top 60 for an inconsequential handful of seconds before hitting the brakes at station or wye approach, at zero difference in schedule time). That study schedule took 10 minutes to go from Windsor Gardens to Foxboro (6 miles) without a Walpole stop (omitted from the scoping study since it's a separate TBD how an ADA'd Walpole Station would be configured), whereas today's Forge Park schedule takes 5 minutes from WG to Walpole (2.5 miles). Splitting the difference, that probably means 5 min. WG-Walpole + 5 min. Walpole-Foxboro if the full-build included a Walpole platform. I guess you can do some math and extrapolate from there how much of an improvement the much zippier Class 3 full-build uprate is from the game trains, as 60 vs. 25 MPH is a much starker difference than 30 vs. 25.

For what it's worth, I took the train to a game last year and according to GPS, we topped out at 9 miles an hour between the wye and the stadium. We also missed the scheduled/published arrival by about 15 minutes, so the upgrades might just translate to meeting the published times.

The pilot has been approved by the MBTA FMCB. From the Boston Globe today:

The board on Monday also approved a one-year pilot service on the commuter rail to Gillette Stadium in Foxborough. Partially subsidized by the Kraft Group, which owns the stadium and the New England Patriots, the service would launch in spring 2019.

The Foxborough proposal had drawn opposition along the Fairmount Line, where riders worried that extending the train service along their tracks to Foxborough increased the risk of delay. Transportation Secretary Stephanie Pollack argued the pilot could help boost ridership and increase parking options along the commuter rail. As part of the Foxborough service, the Krafts will provide 500 parking spaces at the stadium for T commuters.

“They are all-star, hall-of-fame caliber when it comes to screwing things up,” state Rep. Shawn Dooley (R-Norfolk) said of the MBTA. “The fact that they’re willing to sacrifice more taxpayer dollars to make their argument (for this pilot) possibly work is beyond me. It just shows a total disregard for the public trust.

Apparently the Conservation Law Foundation is now a "civil rights" organization:

“That means the folks riding from Foxboro will be sitting and the folks getting on board on the Fairmount Line will be standing,” said Rafael Mares of the Conservation Law Foundation. “And if you know the demographics, that means that most white people coming from Foxboro will be sitting while black people will be standing, which is a terrible image.”

Current Temporary Speed Restriction on the Framingham Secondary for passenger trains is 10 mph for the entire branch. As someone mentioned, MassCoastal has been very busy this summer replacing ties, and the last 3 weeks, dumping stone, and having the track tamped and surfaced. Stone dumping will be wrapping up in a few weeks, and then the rail will be replaced before the speed is brought back up. Along with x'ing upgrades, etc. that is also needed